The fifth season of the dark humor series, with among others Gary Oldman in the roles, will be Smith's last. He has now handed over the pen to Gaby Chiappe ("The beast must die", "Their finest") who has written the sixth season of the successful series, according to Dark Horizons.
It was also recently announced that the series will get a seventh season, which will start filming in the fall and is written by Ben Vanstone ("A gentleman in Moscow", "All creatures great and small").
Smith is not the only creator behind high-profile TV series who is now leaving. Matt Owens is quitting "One piece" after its second season and Neil Druckman has recently jumped off "The last of us".
"Slow horses" follows a department within the British intelligence service that functions as a kind of dumping ground for misfit agents.
